body {
            font-family: 'Segoe UI', Arial, sans-serif;
            background: linear-gradient(to bottom, #f0f7f7, #e0f2f1);
            margin: 0;
            padding: 0;
            color: #333;
        }
        header {
            background: linear-gradient(to right, #006666, #008080);
            color: white;
            padding: 40px 20px;
            text-align: center;
            box-shadow: 0 4px 10px rgba(0,0,0,0.2);
        }
        header h1 {
            margin: 0;
            font-size: 2.5em;
        }
        nav {
            background-color: #004d4d;
            padding: 15px;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
        nav ul {
            list-style: none;
            padding: 0;
            margin: 0;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
        }
        nav ul li {
            margin: 8px 15px;
        }
        nav ul li a {
            color: #fff;
            text-decoration: none;
            font-weight: bold;
            padding: 8px 12px;
            border-radius: 5px;
            transition: background 0.3s;
        }
        nav ul li a:hover {
            background-color: #008080;
        }
        .container {
            max-width: 1200px;
            margin: 30px auto;
            padding: 20px;
        }
        .section {
            margin-bottom: 40px;
            background: white;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 6px 15px rgba(0,0,0,0.1);
        }
        .accordion {
            cursor: pointer;
            padding: 20px;
            background: linear-gradient(to right, #b2dfdb, #80cbc4);
            font-size: 1.3em;
            font-weight: bold;
            color: #004d4d;
            transition: background 0.4s;
        }
        .accordion:hover {
            background: linear-gradient(to right, #80cbc4, #4db6ac);
        }
        .panel {
            display: none;
            padding: 25px;
            background-color: #f9f9f9;
        }
        .panel p {
            line-height: 1.6;
        }
        .flip-card {
            background-color: transparent;
            width: 320px;
            height: 220px;
            perspective: 1000px;
            margin: 25px auto;
        }
        .flip-card-inner {
            position: relative;
            width: 100%;
            height: 100%;
            text-align: center;
            transition: transform 0.9s cubic-bezier(0.68, -0.55, 0.27, 1.55);
            transform-style: preserve-3d;
            border-radius: 15px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.15);
        }
        .flip-card:hover .flip-card-inner {
            transform: rotateY(180deg);
        }
        .flip-card-front, .flip-card-back {
            position: absolute;
            width: 100%;
            height: 100%;
            backface-visibility: hidden;
            border-radius: 15px;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
            box-sizing: border-box;
        }
        .flip-card-front {
            background: linear-gradient(135deg, #008080, #004d4d);
            color: white;
            font-size: 1.4em;
            font-weight: bold;
        }
        .flip-card-back {
            background: linear-gradient(135deg, #004d4d, #002b2b);
            color: #e0f7fa;
            transform: rotateY(180deg);
            font-size: 1.1em;
        }
        table {
            width: 100%;
            border-collapse: collapse;
            margin: 20px 0;
        }
        table th, table td {
            border: 1px solid #80cbc4;
            padding: 12px;
            text-align: left;
        }
        table th {
            background-color: #008080;
            color: white;
        }
        table tr:nth-child(even) {
            background-color: #e0f2f1;
        }
        footer {
            text-align: center;
            padding: 20px;
            background-color: #004d4d;
            color: white;
            margin-top: 50px;
        }